A fire at an Irish Water facility is being investigated by gardaí.
The blaze was at a premises housing water meters in Union Place in Sligo town.
Sligo Fire Brigade said the blaze was retained to a single-storey unit after the alert was raised at 6.05am.
Nobody was in the building at the time.
Gardaí carried out a forensic examination and said that while investigations into the cause of the fire were continuing, they believed the circumstances are suspicious.
The building is occupied by GMC/Sierra, which has been appointed by Irish Water to install meters in the northwest.